The amounts of inorganic elements in cooperage oak

The 9 main inorganic elements in wood were assayed by atomic absorption after mineralisation. The position of the sample in the trunk had a significant influence on the inorganic composition of the wood. There were larger amounts of divalent cations such as magnesium, manganese and calcium at the base of the trunk, whereas monovalent alkalines were more abundant in the higher parts of the trees. The position of the wood in relation to the cardinal points was another source of variability, even though the Variations observed resulted from differences in ring width from one orientation to another. The radial gradient of inorganic substances was characterised by higher levels in the sapwood than the heartwood. In comparison of samples of different origins, the wood from pedunculate oaks from the Limousin region was significantly richer in iron than the wood of sessile oaks and American white oaks. Sessile oak wood contained more manganese and less magnesium and calcium than pedunculate oak wood and white oak wood.